Kentucky Horse Dead from EEE

Kentucky officials have confirmed that a Hart County horse was diagnosed with Eastern equine encephalitis (EEE) and died last week. This is the first confirmed case of EEE affecting a horse in Kentucky since 2008 and only the second reported naturally infected horse in the state since 1995.

The diagnosis was based on clinical presentation consistent with EEE infection and positive ELISA testing reported by USDA's National Veterinary Services Laboratory, an official statement from the Kentucky State Veterinarian’s office said.

The 10-year-old Tennessee Walking Horse gelding died from the disease on Aug. 18, two days after the onset of clinical signs. The horse had no vaccination history for West Nile virus or EEE in the last 36 months and no recent travel history. The remaining 19 horses on the premises showed no signs of EEE and received vaccination against the disease on Aug. 17.

This viral disease affects the central nervous system and is transmitted to horses by infected mosquitoes. Clinical signs of EEE include moderate to high fever, depression, lack of appetite, cranial nerve deficits (facial paralysis, tongue weakness, difficulty swallowing), behavioral changes (aggression, self-mutilation, or drowsiness), gait abnormalities, or severe central nervous system signs such as head-pressing, circling, blindness, and seizures.

The course of EEE can be swift, with death occurring two to three days after onset of clinical signs despite intensive care; fatality rates reach 75-80% among horses. Horses that survive might have long-lasting impairments and neurologic problems.

About the Author

Michelle Anderson serves as The Horse's digital managing editor. In her role, she produces content for our web site and hosts our live events, including Ask the Vet Live. A lifelong horse owner, Anderson competes in dressage and enjoys trail riding. She's a Washington State University graduate (Go Cougs!) and holds a bachelor's degree in communications with a minor in business administration and extensive coursework in animal sciences. She has worked in equine publishing since 1998. She currently lives with her husband on a small horse property in Central Oregon.

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